[The common definition of estimate is] "the most optimistic prediction that has a non-zero probability of coming true." ... Accepting this definition leads irre

[The common definition of estimate is] "the most optimistic prediction that has a non-zero probability of coming true." ... Accepting this definition leads irrevocably toward a method called what's-the-earliest-date-by-which-you-can't-prove-you-won't-be-finished estimating. -- Tom DeMarco ---- as quoted in the book, "Software Estimation" by Steve McConnell.